/**
 ******************************************************************************
 *
 * @file       pios_com.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 *             Parts by Thorsten Klose (tk@midibox.org)
 * @brief      COM layer functions
 * @see        The GNU Public License (GPL) Version 3
 * @defgroup   PIOS_COM COM layer functions
 * @{
 *
 *****************************************************************************/
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */


/* Project Includes */
#include "pios.h"

#if defined(PIOS_INCLUDE_COM)

#include <pios_com_priv.h>

static struct pios_com_dev *find_com_dev_by_id(uint8_t port)
{
    if (port >= pios_com_num_devices) {
        /* Undefined COM port for this board (see pios_board.c) */
        return NULL;
    }

    /* Get a handle for the device configuration */
    return &(pios_com_devs[port]);
}

/**
 * Initialises COM layer
 * \param[in] mode currently only mode 0 supported
 * \return < 0 if initialisation failed
 */
int32_t PIOS_COM_Init(void)
{
    int32_t ret = 0;

    /* If any COM assignment: */
#if defined(PIOS_INCLUDE_SERIAL)
    PIOS_SERIAL_Init();
#endif

#if defined(PIOS_INCLUDE_UDP)
    PIOS_UDP_Init();
#endif

    return ret;
}

int32_t PIOS_COM_Close(void)
{
    int32_t ret = 0;

#if defined(PIOS_INCLUDE_UDP)
    PIOS_UDP_Close();
#endif

    return ret;
}

/**
 * Change the port speed without re-initializing
 * \param[in] port COM port
 * \param[in] baud Requested baud rate
 * \return -1 if port not available
 * \return 0 on success
 */
int32_t PIOS_COM_ChangeBaud(uint8_t port, uint32_t baud)
{
    struct pios_com_dev *com_dev;

    com_dev = find_com_dev_by_id(port);

    if (!com_dev) {
        /* Undefined COM port for this board (see pios_board.c) */
        return -1;
    }

    /* Invoke the driver function if it exists */
    if (com_dev->driver->set_baud) {
        com_dev->driver->set_baud(com_dev->id, baud);
    }

    return 0;
}

/**
 * Sends a package over given port
 * \param[in] port COM port
 * \param[in] buffer character buffer
 * \param[in] len buffer length
 * \return -1 if port not available
 * \return -2 if non-blocking mode activated: buffer is full
 *            caller should retry until buffer is free again
 * \return 0 on success
 */
int32_t PIOS_COM_SendBufferNonBlocking(uint8_t port, uint8_t *buffer, uint16_t len)
{
    struct pios_com_dev *com_dev;

    com_dev = find_com_dev_by_id(port);

    if (!com_dev) {
        /* Undefined COM port for this board (see pios_board.c) */
        return -1;
    }

    /* Invoke the driver function if it exists */
    if (com_dev->driver->tx_nb) {
        return com_dev->driver->tx_nb(com_dev->id, (char *)buffer, len);
    }

    return 0;
}

/**
 * Sends a package over given port
 * (blocking function)
 * \param[in] port COM port
 * \param[in] buffer character buffer
 * \param[in] len buffer length
 * \return -1 if port not available
 * \return 0 on success
 */
int32_t PIOS_COM_SendBuffer(uint8_t port, uint8_t *buffer, uint16_t len)
{
    struct pios_com_dev *com_dev;

    com_dev = find_com_dev_by_id(port);

    if (!com_dev) {
        /* Undefined COM port for this board (see pios_board.c) */
        return -1;
    }

    /* Invoke the driver function if it exists */
    if (com_dev->driver->tx) {
        return com_dev->driver->tx(com_dev->id, (char *)buffer, len);
    }

    return 0;
}

/**
 * Sends a single character over given port
 * \param[in] port COM port
 * \param[in] c character
 * \return -1 if port not available
 * \return -2 buffer is full
 *            caller should retry until buffer is free again
 * \return 0 on success
 */
int32_t PIOS_COM_SendCharNonBlocking(uint8_t port, char c)
{
    return PIOS_COM_SendBufferNonBlocking(port, (uint8_t *)&c, 1);
}

/**
 * Sends a single character over given port
 * (blocking function)
 * \param[in] port COM port
 * \param[in] c character
 * \return -1 if port not available
 * \return 0 on success
 */
int32_t PIOS_COM_SendChar(uint8_t port, char c)
{
    return PIOS_COM_SendBuffer(port, (uint8_t *)&c, 1);
}

/**
 * Sends a string over given port
 * \param[in] port COM port
 * \param[in] str zero-terminated string
 * \return -1 if port not available
 * \return -2 buffer is full
 *         caller should retry until buffer is free again
 * \return 0 on success
 */
int32_t PIOS_COM_SendStringNonBlocking(uint8_t port, char *str)
{
    return PIOS_COM_SendBufferNonBlocking(port, (uint8_t *)str, (uint16_t)strlen(str));
}

/**
 * Sends a string over given port
 * (blocking function)
 * \param[in] port COM port
 * \param[in] str zero-terminated string
 * \return -1 if port not available
 * \return 0 on success
 */
int32_t PIOS_COM_SendString(uint8_t port, char *str)
{
    return PIOS_COM_SendBuffer(port, (uint8_t *)str, strlen(str));
}

/**
 * Sends a formatted string (-> printf) over given port
 * \param[in] port COM port
 * \param[in] *format zero-terminated format string - 128 characters supported maximum!
 * \param[in] ... optional arguments,
 *        128 characters supported maximum!
 * \return -2 if non-blocking mode activated: buffer is full
 *         caller should retry until buffer is free again
 * \return 0 on success
 */
int32_t PIOS_COM_SendFormattedStringNonBlocking(uint8_t port, char *format, ...)
{
    uint8_t buffer[128]; // TODO: tmp!!! Provide a streamed COM method later!

    va_list args;

    va_start(args, format);
    vsprintf((char *)buffer, format, args);
    return PIOS_COM_SendBufferNonBlocking(port, buffer, (uint16_t)strlen((char *)buffer));
}

/**
 * Sends a formatted string (-> printf) over given port
 * (blocking function)
 * \param[in] port COM port
 * \param[in] *format zero-terminated format string - 128 characters supported maximum!
 * \param[in] ... optional arguments,
 * \return -1 if port not available
 * \return 0 on success
 */
int32_t PIOS_COM_SendFormattedString(uint8_t port, char *format, ...)
{
    uint8_t buffer[128]; // TODO: tmp!!! Provide a streamed COM method later!
    va_list args;

    va_start(args, format);
    vsprintf((char *)buffer, format, args);
    return PIOS_COM_SendBuffer(port, buffer, (uint16_t)strlen((char *)buffer));
}

/**
 * Transfer bytes from port buffers into another buffer
 * \param[in] port COM port
 * \returns Byte from buffer
 */
uint8_t PIOS_COM_ReceiveBuffer(uint8_t port)
{
    struct pios_com_dev *com_dev;

    com_dev = find_com_dev_by_id(port);
    // PIOS_DEBUG_Assert(com_dev);
    // PIOS_DEBUG_Assert(com_dev->driver->rx);

    return com_dev->driver->rx(com_dev->id);
}

/**
 * Get the number of bytes waiting in the buffer
 * \param[in] port COM port
 * \return Number of bytes used in buffer
 */
int32_t PIOS_COM_ReceiveBufferUsed(uint8_t port)
{
    struct pios_com_dev *com_dev;

    com_dev = find_com_dev_by_id(port);

    if (!com_dev) {
        /* Undefined COM port for this board (see pios_board.c) */
        return 0;
    }

    if (!com_dev->driver->rx_avail) {
        return 0;
    }

    return com_dev->driver->rx_avail(com_dev->id);
}

#endif /* if defined(PIOS_INCLUDE_COM) */
